This climbing cactus is found in the deserts of Central America and the southern US, and is renowned for its beautiful, bat-friendly blooms that open around sundown and wither soon after sunrise. It is notoriously difficult to cultivate: horticulturalist Eli Biondi tends a single specimen at London's Royal Botanic Gardens, Kew, but has also seen them in the wild in Arizona. "The flower is pretty impressive," she says, although you may have to wait a long time to see one: the plants are often 20 years old before they flower. Even then, the chance is fleeting as the bloom closes and shrivels within hours. "That flower must be pollinated on that one night, which is why it is so showy," Biondi says. It has a powerful aroma too, that earned the plant the nickname "vanilla cactus". This scent, along with the stability provided by very long petals and sepals – tiny leaves just beneath the bloom – draws Mexican long-tongued bats and lesser long-nosed bats to it as a humid haven in the desert. The blooms can survive for a few hours after dawn, a chance to draw in daytime pollinators. "It's sort of a back-up plan," says Biondi.